rf3230 RF Micro Devices, rf3230 Datasheet - Page 14

• Manufacturer Part Number: rf3230
• Description: Quad-band Gmsk Txm, 2 Umts Switch Ports
• Manufacturer: RF Micro Devices

RF3230
Module Control Timing
In the Power-On Sequence, there are some important set-up times associated with the control signals of the TxM. Refer to the
logic table for control signal functions. One of the critical relationships is the settling time between selecting TX mode and
when V
control loop and bias circuitry can settle after being turned on. The PowerStar® architecture usually requires approximately
1μs to 2μs for proper settling of the power control loop.
Power Ramping
The V
ramp the RF output power to meet ETSI switching transient and time mask requirements partially depends upon the predict-
ability of output power versus V
switching transient requirements with the proper raised cosine waveform applied to the V
10μs and 14μs can be optimized to provide excellent switching transients at high power levels. Shorter ramps will have a
higher rate of change which will produce higher transients. Longer ramps may have difficulty meeting the time mask. Optimi-
zation needs to include all power levels as the time mask requirements change with P
The RF3230 does not include a power control loop detection/correction circuit such as the V
PowerStar modules. If V
of the regulated voltage (V
and the output power does not follow the desired ramp-down curve. The result is a discontinuity in the output power ramp and
degraded switching transients. To prevent this from happening, V
maintaining V
dation will be avoided.
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RAMP
RAMP
waveform must be created such that the output power falls into the ETSI power versus time mask. The ability to
can begin to increase. This time is often referred to as the “pedestal” and is required so that the internal power
RAMP
≤0.345*V
RAMP
CC
) slows significantly. Upon ramp-down, the saturated linear regulator does not react immediately,
is set to a voltage where the FET pass-device in the linear regulator saturates, the response time
BATT
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RAMP
+0.26, the linear regulator will avoid deep saturation and serious switching transient degra-
response of the power amplifier. The PowerStar® control loop is very capable of meeting
GMSK Power On/Off Sequence
RAMP
must be limited as the supply voltage is reduced. By
OUT
levels.
RAMP
BATT
tracking circuit found in some
input. Ramp times between
DS100406